"We are pleased the Court has agreed to hear this case," said White House spokesman Dan Pfeiffer in a Tweet. "We know the ACA [Affordable Care Act] is constitutional and are confident the Supreme Court will agree."

In a longer statement put out by the White House, Pfeiffer said, "Earlier this year, the Obama Administration asked the Supreme Court to consider legal challenges to the health reform law and we are pleased the Court has agreed to hear this case. Thanks to the Affordable Care Act, one million more young Americans have health insurance, women are getting mammograms and preventive services without paying an extra penny out of their own pocket and insurance companies have to spend more of your premiums on health care instead of advertising and bonuses. We know the Affordable Care Act is constitutional and are confident the Supreme Court will agree."

The Supreme Court is setting aside a remarkable five-and-a-half hours for oral argument on the health care cases. It has yet to set a date for these historic arguments, though they will likely come in late February or early March.

The time breakdown is as follows:

- 2 hours on the "individual mandate," the requirement that virtually all Americans buy health insurance

- 1.5 hours on whether, if the mandate is unconstitutional, the rest of the law still stands, or whether it must fall as well

- 1 hour on the law's new Medicaid requirements on the states

- 1 hour on whether the courts can hear challenges to the law now, or whether they must wait until the mandate actually takes effect in 2014.